JP2010162673A - Method for arranging nanostructure, method for preparing nanodevice, and substrate for nanodevice preparation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for arranging nanostructures which can achieve reliable arrangement of nanostructures in a gap between electrodes and to provide a method for preparing a nanodevice using the method and a substrate for nanodevice preparation. <P>SOLUTION: While forming an alternating electric field between a first electrode 11 and a second electrode 12 provided on an identical line while providing a space therebetween, a dispersion in which a plurality of nanostructures are mixed is allowed to flow in a flow path defined along the direction of arrangement of the first electrode 11 and the second electrode 12, whereby the nanostructures in the dispersion are arranged so as to astride the first electrode 11 and the second electrode 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nanostructure arraying method in which nanowires, nanorods, and other nanostructures are arrayed in an electrode gap, a nanodevice manufacturing method to which the method is applied, and a nanodevice manufacturing substrate.

  Recently, nanotubes, nanowires, nanorods and other one-dimensional nanostructures can be manufactured. For example, Non-Patent Documents 1 to 4 are known as methods for producing ZnO nanowires. Accordingly, research and development of nanodevices using nanostructures is underway.

  On the other hand, when an electric field is applied to a dispersion (also referred to as “dispersion system”) in which a dispersoid such as particles is dispersed in a dispersion medium such as a solution, the electrophoretic (DEEP) phenomenon, that is, the dispersion medium and the dispersion medium are dispersed. Induced dipole moment is generated by the difference in polarizability from the quality, and the difference in electric field strength formed on both sides of the dispersoid becomes the difference in force exerted by the induced dipole, and the force acts on the dispersoid such as particles. It has been known. When the dispersoid is a linear molecule, it is known that the linear molecule is elongated by induction electrophoresis. There are research examples (for example, Non-Patent Document 5) in which DNA is oriented in the vertical direction with respect to opposing electrodes by using this induced electrophoresis phenomenon for cell manipulation and patterning (for example, Patent Document 1). Further, attention has been focused on using positive dielectrophoresis when fixing one end of a nanowire as an AFM probe (for example, Non-Patent Documents 6 to 7). For example, it is reported that an AFM probe and a CNT (Carbon nanotube) are well coupled by a positive induced electrophoresis pulse voltage having a peak-to-peak voltage of 10 V and a frequency of 2 MHz. Thus, it is considered effective to use positive dielectrophoresis when fixing one end of the nanostructure.

  As an example of arranging nanowires between electrode gaps, for example, in Patent Document 9, 30 μl of a carbon nanotube (CNT) suspension is dropped, and 6 DEP pulses are applied between a pair of electrodes at a peak-to-peak voltage of 2 V and a frequency of 300 kHz. It has been successfully applied for a minute to place CNTs in an electrode gap of about 1 μm, producing a single nanowire device. Patent Document 10 reports that 90% or more of CNT nanowires are bonded in a device having 400 pairs of electrodes as an application example of a multi-channel device.

WO2008 / 001742

M. H. Huang et al, Adv. Mater. 13, 113-116 (2001) S. H. Lee et al J. Nanosci. Nanotech. 6, 3351-3354 (2006) S. H. Lee et al J Phys Chem B 110, 3856-3859 (2006) S. H. Lee et al Nano Lett. 8, 2419-2422 (2008) H. Kabata et al, Science 262, 1561-1563 (1993) J. Zhang et al, Adv. Mater. 16, 1219- (2004) J. Tang et al, Nano Lett., 5, 11-14 (2005) R. Krupke ae al, Nano Lett., 4, 1395-1399 (2004) M. Oron-Carl et al, Nano Lett. 5, 1761-1767 (2005) A. Vijayaraghavan et al, Nano Lett., 7, 1556-1560 (2007)

  However, according to the methods disclosed in Patent Document 1 and Non-Patent Document 5, one nanostructure cannot be selectively oriented and captured in the electrode gap. Moreover, in nanodevices such as FET (Field Effect Transistor) type, it is necessary to join each end of the nanostructure to different electrodes. Otherwise, various logic circuits and sensing devices cannot be constructed due to the conduction characteristics of nanostructures such as nanowire carriers, that is, electrons and holes.

  Capturing microparticles based on dielectrophoretic force is now becoming a very common technique, but it is stochastically very difficult to capture each end of nanostructures such as nanowires and nanorods simultaneously It is. In other words, applying an inductive electrophoresis pulse voltage between electrodes makes it difficult to reliably place nanostructures between the electrodes, which not only reduces the manufacturing efficiency of various nanodevices using nanostructures, but is also constant. There is a problem that the quality of can not be maintained.

  The method disclosed in Patent Document 9 is applicable only when the electrode gap is relatively short, less than 1 μm, because the electrophoretic force is weak, and the application time of the electrophoretic pulse voltage is also relatively long at 6 minutes. . If the application time of the inductive electrophoresis pulse voltage is long, the inductive electrophoretic pulse promotes the electrochemical reaction or chemical change of the nanowire, so that the nanowire may be deteriorated. Therefore, the performance quality of the device is deteriorated. Moreover, Patent Document 9 describes that the success rate when arranging single nanowires remains at 3/18, and the productivity is poor.

  Patent Document 10 explains that when a single nanowire is arranged in the gap between two electrodes by dielectrophoresis, the electric field gradient in the vicinity of the two electrodes changes and repulsive force acts on the second and subsequent nanowires. Has been. However, when the inventors conducted a similar experiment, such a phenomenon was not observed, and a plurality of nanowires were arranged in the gap of the electrodes. Further, the phenomenon described in Patent Document 10 is not general.

  Accordingly, the present invention provides a method for arranging nanostructures, a method for producing nanodevices using the same, and a substrate for producing nanodevices, which can reliably arrange the nanostructures in the electrode gap. Objective.

  The inventors of the present invention have conducted extensive research and previously orienting the nanostructure in parallel with the line connecting the two points so that nanostructures such as nanowires and nanorods can be simultaneously captured at the two points. It was considered that the efficiency of capturing nanostructures such as nanowires and nanorods between the two electrodes would be greatly improved. Then, when the nanostructure moves in the laminar flow, attention is paid to a phenomenon in which the major axis direction of the nanostructure is aligned in parallel with the moving direction. That is, in order to orient nanostructures such as nanowires and nanorods in advance, a channel having a micro-size width (referred to as “microchannel”) is used, and a microchannel and induction electrophoresis are used. The inventors have found that it is extremely effective for arranging nanostructures between electrodes, and have completed the present invention.

In the method for arranging nanostructures according to the present invention, the first electrode and the second electrode are arranged while an alternating electric field is formed between the first electrode and the second electrode which are provided at intervals. The nanostructures are arranged so as to straddle the first electrode and the second electrode by flowing a dispersion in which a plurality of nanostructures are mixed in the flow path defined along the direction. It is characterized by doing.
In the above configuration, the end of the first electrode on the second electrode side becomes narrower as it becomes the tip, and the end of the second electrode on the first electrode side becomes the tip. The width is preferably narrow.

In the method for producing a nanodevice in the present invention, a step of forming a first electrode and a second electrode on a substrate with a space therebetween, and an arrangement direction of the first electrode and the second electrode on the substrate. A flow path along the flow path, and a dispersion in which a plurality of nanostructures are mixed is applied to the flow path while applying an alternating voltage between the first electrode and the second electrode. Capturing between the first electrode and the second electrode, and disposing the nanostructure so as to straddle the first electrode and the second electrode.
In the above configuration, the step of removing the flow path forming portion that defines the flow path, and forming the first conductive electrode on one end of the nanostructure and the first electrode, Forming a second conducting electrode on the other end and the second electrode.
In the above configuration, the end of the first electrode on the second electrode side becomes narrower as it becomes the tip, and the end of the second electrode on the first electrode side becomes the tip. The width is preferably narrow.

The substrate for producing a nanodevice according to the present invention includes a base, a first electrode provided on the base, a second electrode provided on the base at a distance from the first electrode, and a first electrode And a flow path forming portion that defines a flow path along the direction in which the nanostructures are to be arranged, which is a gap between the second electrodes.
In the above structure, a nanostructure may be disposed between the first electrode and the second electrode.

  According to the method for arranging nanostructures in the present invention, the nanostructures are transported in advance by a dispersion medium along a flow path provided in parallel to the gap between the first electrode and the second electrode. By controlling the orientation of the nanostructure and applying an alternating voltage between the two electrodes, the nanostructure can be reliably captured between the electrodes by induction electrophoresis. That is, the nanostructures can be efficiently and reliably arranged between the electrode gaps by using the flow path and the induction electrophoresis.

  According to the method for producing a nanodevice according to the present invention, a flow path is provided in parallel to the gap between the first electrode and the second electrode, a dispersion containing a nanostructure is introduced from the flow path port, The first electrode and the second electrode are produced by transporting the nanostructure along the path by a dispersion medium and causing an induced migration by applying an alternating voltage between the first electrode and the second electrode. The nanostructure is reliably captured between the two. By using the flow path and the dielectrophoresis as described above, the nanostructures can be efficiently and reliably arranged so as to straddle between the first electrode and the second electrode. Moreover, a semiconductor device and various sensing devices can be produced by ensuring electrical continuity at both ends of the nanostructure.

  According to the substrate for producing a nanodevice according to the present invention, the flow path is formed along the arrangement direction so that the first electrode and the second electrode have a gap. By introducing a dispersion containing a body, a single nanostructure can be efficiently arranged across the first electrode and the second electrode, and the productivity of a single nanodevice is improved. In addition, the production cost of a single nanodevice can be reduced.

The nanostructure arrangement | sequence chip | tip used in the case of the arrangement method of the nanostructure which concerns on one Embodiment of this invention is shown, (A) is a top view, (B) is a front view. It is a figure which shows the calculation result of the frequency characteristic dependence of Re [K ((omega))] in case a nanostructure is a ZnO nanowire. It is a figure which shows the calculation result of the frequency characteristic dependence of Re [K ((omega))] in case a nanostructure is s-SWNT. It is a figure which shows the calculation result of the frequency characteristic dependence of Re [K ((omega))] in case a nanostructure is MWNT. It is a top view of the nanodevice concerning the embodiment of the present invention. It is the elements on larger scale which show the gap area | region vicinity of the 1st electrode and 2nd electrode which are shown in FIG. It is sectional drawing which follows the AA line of FIG. It is a top view of another nanodevice concerning the embodiment of the present invention. It is sectional drawing which follows the BB line of FIG. It is sectional drawing which follows the CC line of FIG. It is a top view which shows 1 process of the process which produces the nanodevice shown in FIG. The ZnO nanowire produced in Example 1 is shown, (A) is a SEM image of what was produced on the board | substrate, (B) is an enlarged image of (A). It is an optical microscope image which shows the dispersion containing a ZnO nanowire. (A) shows device mask designs such as first, second, and third electrodes, and (B) is a diagram showing a device mask pattern at the time of microchannel lamination. (A) is an SEM image of the electrode substrate actually produced, and (B) is an SEM image in a state where the electrode substrate and the flow path substrate are actually bonded. 14A is a simulation result of an electric field gradient when an alternating voltage is applied to the first electrode and the second electrode shown in FIG. 14A, and FIG. 14A is a predetermined height from the first electrode and the second electrode. The figure which shows the electric field gradient in the surface of FIG. 9 by a light and shade, (B) is a figure which shows the light and dark of the electric field gradient in a vertical cross section direction. It is a figure which shows the SEM image containing the ZnO nanowire trapped between between electrodes. (A) is a figure which shows the current-voltage characteristic of the produced nanodevice, (B) is a figure which shows the current-voltage characteristic when light with a different wavelength is irradiated to a nanostructure. (A) is a figure which shows the result of the current transient characteristic with respect to UV light irradiation ON / OFF with respect to the nanodevice produced in the present Example, (B) is a figure which shows the result of the current transient characteristic of a ZnO thin film substrate. 2 is an SEM image of an FET type nanodevice fabricated as Example 2. FIG. 6 is a current-voltage characteristic diagram of an FET type nanodevice fabricated as Example 2. Is a diagram showing the _I SD _{-V SD} characteristics in EFT nano device. When fixing the V _SD to 0.5V, _I SD for _{V G,} it is a diagram illustrating a measured result indicating a relation between _{I G.}

  Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, what is described below can be appropriately changed without departing from the spirit of the present invention, and is also included in the scope of the present invention. .

[Method for arranging nanostructures]
A method for arranging nanostructures according to an embodiment of the present invention will be described.
1A and 1B show a nanostructure array chip 10 used for arraying nanostructures according to an embodiment of the present invention, where FIG. 1A is a plan view and FIG. 1B is a front view.
Here, the arrangement method of the nanostructures is, for example, as shown in FIG. 1, on the base 13 so that the first electrode 11 and the second electrode 12 have a gap on the same axis, that is, in plan view. In this case, the first electrode 11 and the second electrode 12 are arranged so as to straddle a one-dimensional nanostructure such as a nanorod or a nanowire. In the first electrode 11 and the second electrode 12, it is preferable that the line width becomes narrower and narrower as the tip portions 11a and 12a facing each other become ends. This is because, as will be described later, when an alternating voltage is applied to the first electrode 11 and the second electrode 12, the electric field strength increases in the vicinity of the tip portions 11a and 12a. In the case shown in the drawing, the distal end portion 11a of the first electrode 11 and the distal end portion 12a of the second electrode 12 both project in a triangular shape in plan view, but if they are pointed, they have other shapes. May be.
As shown in FIGS. 1 (A) and 1 (B), the nanostructure array chip 10 has a flow path 17 so as to be parallel to the gap between the first electrode 11 and the second electrode 12, that is, the gap. Preferably, a channel 17 having a micro-sized width is formed. That is, the flow path 17 is formed so as to sandwich the first electrode 11 and the second electrode 12 formed on the same axis and to be parallel to the direction connecting the first electrode 11 and the second electrode 12. Has been. Specifically, the first electrode 11 and the second electrode 12 are disposed on the base 13 with a predetermined gap therebetween, and further, parallel to the gap between the first electrode 11 and the second electrode 12. A flow path 17 is provided in the front. The flow path 17 is on the base 13 and in parallel with the arrangement direction of the first electrode 11 and the second electrode 12, the first flow path forming section 15 and the second flow path forming section 16. The first flow path forming part 15 and the second flow path forming part 16 are arranged with the first electrode 11 and the second electrode 12 in between so as to face each other. A flow path 17 is defined by the first flow path forming section 15 and the second flow path forming section 16. Note that the flow path 17 defined by the first flow path forming section 15 and the second flow path forming section 16 has an inlet and an outlet (at the position away from the first electrode 11 and the second electrode 12). Neither is shown). The inlet and the outlet may be provided so as to be orthogonal to the upper and lower surfaces of the base bodies 13 and 14 and to face each other in the direction in which the flow path 17 extends, and the inlet is formed on the upper face of the base body 14 positioned vertically upward. The outlet may be provided on the lower surface of the base 13 positioned vertically below. In the form shown in FIGS. 1A and 1B, the first flow path forming portion 15 and the second flow path forming portion 16 are sandwiched between the base body 13 and the base body 14 and arranged separately. However, the present invention is not limited to this, and as will be described later, the cross section orthogonal to the flow path 17 may be configured by a single flow path forming portion having a U-shape.

Here, the first electrode 11 is formed in a linear shape parallel to the first flow path forming portion 15, and crosses and is coupled to the first external connection electrode 18 at the end portion 11 b opposite to the tip end portion 11 a. Yes. The first external connection electrode 18 extends linearly to the outside of the first flow path forming portion 15 so as to intersect with the flow path 17 on the base 13, and orthogonally in the illustrated example.
The second electrode 12 is formed in a linear shape parallel to the second flow path forming portion 16, and crosses and is coupled to the second external connection electrode 19 at the end portion 12 b opposite to the tip end portion 12 a. The second external connection electrode 19 extends to the outside of the second flow path forming portion 16 on the base 13 so as to intersect with the flow path 17 and orthogonally cross in the illustrated example.
The first electrode 11 and the first external connection electrode 18 are composed of the same metal layer, and the second electrode 12 and the second external connection electrode 19 are composed of the same metal layer. Here, each metal layer preferably has a laminated structure of an adhesion layer made of titanium or the like and an electrode layer on a base 13 made of a glass substrate or a quartz substrate.
In the embodiment shown in FIGS. 1A and 1B, the first external connection electrode 18 and the second external connection electrode 19 intersect the flow path 17 and extend in opposite directions, respectively. , Which intersects the flow path 17 and may extend in the same direction.

The outer end 18a of the first external connection electrode 18 and the outer end 19a of the second external connection electrode 19 are connected to a power source (not shown) by wiring. While applying an alternating voltage between the first outer end 18a and the second outer end 19a, that is, while applying an alternating voltage between the first electrode 11 and the second electrode 12, the nanowire A dispersion in which a nanostructure such as a nanodot is dispersed in a dispersion medium is introduced into the flow path 17. At that time, the flow is made to be a laminar flow along the flow path 17. Here, in order to obtain a laminar flow, the Reynolds number Re only needs to be 2000 or less. This Reynolds number Re is: the flow path width d [m] × fluid average flow velocity u [ms ⁻¹ ]) × fluid density ρ [kg · m ⁻³ ] ÷ fluid viscosity μ [kgm ⁻¹ s ⁻¹ ] Defined by Nanostructures such as nanowires are aligned in parallel with the flow path 17 and move through the flow path 17 while maintaining the alignment state. An alternating electric field is formed in a local region between the first electrode 11 and the second electrode 12, and in particular, an inhomogeneous electric field is formed in the vicinity of the first electrode 11 and the second electrode 12. Therefore, a dielectrophoretic force proportional to the second derivative of the electric field strength acts on the nanostructure, and the nanostructure is arranged in the gap between the first electrode 11 and the second electrode 12.

  In this way, the nanostructure is oriented in advance so as to be parallel to a line connecting the two ends of the nanostructure, that is, the tip 11a of the first electrode 11 and the tip 12a of the second electrode 12. By doing so, the probability that the nanostructure is captured between the first electrode 11 and the second electrode 12 jumps.

  Here, the alternating voltage applied to the first electrode 11 and the second electrode 12 is selected to have an appropriate frequency. As a result, positive dielectrophoresis can act on the nanostructure, and the nanostructure can be pulled in the direction in which the electric field strength is high.

A reasonable frequency can be predicted from the simulation results. Therefore, the theoretical calculation of the induced electrophoretic force will be described.
The force acting by dielectrophoresis, that is, induced repulsive force (also referred to as “DEP force”) is expressed by Formula 1 when the dispersoid is a spherical fine particle having a radius a (m). It can be seen from Equation 1 that the DEP force <F _DEP (t)> is proportional to the second-order differential ∇ | E | ² of the electric field strength E.
<F _DEP (t)> = 2πa ³ ε _m Re [K (ω)] ∇ | E | ² (Formula 1)
Here, K (ω) is called a Clausius-Mossoti factor and is represented by a complex number. When the real part is expressed as Re [K (ω)], Re [K (ω)] is expressed by Equation 2 when the fine particles on which the force acts are spherical.
Re [K (ω)] = Re [(ε _p −ε _m ) / (ε _p + 2ε _m )]
= {4f ² π ² (-2ε _m ² + ε _m ε _p + ε _p ² ) -2σ _m ² + σ _m σ _p + σ _p ² } / {4f ² π ² (2ε _m + ε _p ) ² + (2σ _m + σ _p ² } (Formula 2)
Incidentally, the conductivity of the sigma _m dispersion medium ^{[Sm -1],} σ _p is the conductivity of dispersoid ^{[Sm -1],} the dielectric constant of epsilon _m of the dispersion medium ^{[Fm -1],} ε _p is the dispersoid Dielectric constant [Fm ⁻¹ ], f is a frequency [Hz], ω is an angular frequency, that is, 2πf.

When the dispersoid is rod-shaped or wire-shaped, the induced electrophoretic force is represented by the following formula 3.
<F _DEP (t)> = Γε _m Re [K (ω)] ∇ | E | ² (Formula 3)
Here, Γ is a nanorod or nanowire geometric factor [m ³ ], and when the dispersoid is a nanorod or nanowire of radius a and length L, the shape factor Γ is π (a ² L) / It is represented by 6. When the dispersoid is rod-shaped or wire-shaped, K (ω) is expressed by Equation 4.
Re [K (ω)] = Re [(ε _p −ε _m ) / ε _m ]
= {4f ² π ² ε _m (ε _p −ε _m ) −σ _m (σ _p −σ _m )} / {4f ² π ² ε _m ² + σ _m ² }
(Formula 4)

Here, Re [K (ω)] determines the direction of the induced electrophoretic force and changes in value depending on the electric field frequency. When Re [K (ω)] is positive, it is called p-DEP, and when it is negative, it is called n-DEP. Frequency of positive and negative interchange of Re [K (ω)] is called the crossover frequency f _0.

2 to 4 show calculation results of the frequency dependence of Re [K (ω)]. FIG. 2 shows the frequency characteristic dependence of Re [K (ω)] when the nanostructure is a ZnO nanowire. FIG. 3 is a diagram showing a calculation result, FIG. 3 is a diagram showing a calculation result of the frequency characteristic dependence of Re [K (ω)] when the nanostructure is s-SWNT (semiconductor-like single-walled nanotube), and FIG. It is a figure which shows the calculation result of the frequency characteristic dependence of Re [K ((omega))] in case a nanostructure is MWNT (multi-walled nanotube). The horizontal axis of each graph is frequency, and the vertical axis is Re [K (ω)]. In addition, the insertion graph in each graph expands and shows only the positive and negative neighboring portions sandwiching zero of Re [K (ω)]. In the calculation, as values such as ε _p and σ _p , values already known from the literature are referred to, and each ε _p of ZnO, s-SWNT, MWNT is set to 9ε _o , 2.5ε _o , 1.0 × 10 ⁴ ε _0, and each σ _p was ⁸ , 1.0 × 10 ⁸ , 1.0 × 10 ⁵ (Sm ⁻¹ ). epsilon ₀ is a dielectric constant in vacuum ^{9.85 × 10 12 C 2 (Nm} 2) -1. As a dispersion medium, ε _m and σ _p of isopropanol were set to 18.6ε _o and 6 × 10 ⁵ (Sm ⁻¹ ), respectively.

If the nanostructure is a nanowire of ZnO, as shown in FIG. 2, cross-over frequency _{f o} is 2MHz, the frequencies below 100kHz shows the value of very large Re [K] as compared with the microparticle size, it is expected This suggests that the positive dielectrophoretic (p-DEP) force is extremely large.
If the nanostructure is s-SWNT, as shown in FIG. 3, the crossover frequency _{f o} is 200MHz, the frequencies below 10MHz shows the value of very large Re [K] as compared with the microparticle size, it is expected This suggests that the positive dielectrophoretic (p-DEP) force is extremely large.
When the nanostructure is MWNT, as shown in FIG. 4, there is no frequency domain in which negative induced migration (n-DEP) acts, and positive induced migration (p-DEP) acts in all frequency ranges. I understand that.

  Here, when the flow path can take a form other than a straight line, when a flexible nanowire dispersion liquid is introduced into the flow path, another pair of electrodes is arranged for each of the inlet and the outlet, and is parallel to the flow path. In this case, an electric field gradient is formed on the surface, and electrophoresis or electropermeable flow is induced to promote the elongation of the nanowire and move it into the channel 17.

  In the method for arranging nanostructures according to the embodiment of the present invention, the nanostructure may have various shapes as long as it is a one-dimensional structure such as a nanowire, a nanorod, a nanotube, or a needle. Nanorods, nanowires, and nanotubes as nanostructures are carbon, ZnO and other semiconductor materials, platinum, gold and other metals, nanotubes existing outside the bacterial membrane, cilia, flagella, DNA and RNA (peptide nucleic acid) , Peptides, proteins and composite materials thereof, and may be isolated. Even for other materials, the conductivity and dielectric constant are defined for each material, and the DEP force obtained under each condition by further considering the conductivity and dielectric constant on the solvent side can be obtained from the above-mentioned equation 3. Easy to predict.

Here, the gap (gap) between the first electrode 11 and the second electrode is preferably in the range of 100 nm to 100 μm. On the other hand, a nanostructure such as a nanowire may have a predetermined length in the range of 1 μm to 200 μm. In this case, the nanostructure such as a nanowire is preferably slightly longer than the gap between the first electrode 11 and the second electrode 12. Specifically, the ratio of the length L of the nanostructure such as a nanowire to the gap length between the first electrode 11 and the second electrode 12 is preferably 1.05 or more. If it is out of these ranges, a sufficient electrophoretic force may not be obtained for arranging a nanostructure such as a nanowire between the first electrode 11 and the second electrode 12, resulting in inconvenience. It is.
The size of the cross section of the nanowire or the like, that is, the effective radii r1 and r2 in the case of an elliptical cross section is preferably 1 nm or more and 500 nm or less. Within this preferable range, the length L of the nanowire satisfies the condition of L >> r1, r2 with respect to the effective radii r1, r2 of the elliptical cross section.

  In particular, it is preferable to use a solvent such as isopropanol as a dispersion medium for dispersing nanostructures such as nanowires, but solvents in which nanostructures such as nanowires are chemically stable can be widely used. For example, when the nanostructure is made of ZnO, it is weak against acids and bases, so an organic solvent such as alcohol or acetone or water can be used. The dispersion medium is not necessarily a liquid, and a gaseous medium such as a rare gas may be used. This is because the nanostructures are aligned in parallel along the flow path 17.

  In particular, the dispersion concentration of nanostructures such as nanowires is preferably 100 or less per microliter. In this concentration range, the possibility of capturing two or more nanowires can be reduced when a nanostructure such as a nanowire is arranged in the electrode gap by combining the flow path 17 and dielectrophoresis. is there.

  Polydimethylsiloxane (PDMS: poly (dimethylsiloxane)) is suitable as a material for the first and second flow path forming portions 15 and 16 that define the flow path 17. This is because when the PDMS channel 17 is used, the first and second electrodes 11 and 12 on which the nanowires are arranged can be detached from the integrated substrate. As other materials, a photosensitive resist such as SU-8, an OHP sheet, a PET sheet, and the like can be used. In the case of using a sheet-like material, the sheet material is disposed in a space other than the flow path, that is, spaces indicated by reference numerals 15 and 16 in FIG. 1, and these sheet materials are used as spacers. In other words, the flow path 17 may be defined by placing a glass substrate or PDMS substrate at the position of the base 14 shown in FIG.

  The applied voltage of the DEP pulse is preferably 1 to 20 V peak to peak.

  According to the method for arranging nanostructures according to the embodiment of the present invention, the time from when a voltage is applied until a nanostructure such as a single nanowire is captured between the electrodes is within one minute, and the efficiency is greatly improved. .

[Nanodevice Fabrication Method and Nanodevice Fabrication Substrate]
A nanodevice manufacturing method and a nanodevice manufacturing substrate according to an embodiment of the present invention will be described. The nanodevice fabrication substrate is obtained by applying the above-described nanostructure array chip 10 used in the nanostructure alignment method to the nanodevice fabrication substrate. The nanodevice fabrication method is realized by adding another step before and after the steps of the nanostructure arrangement method described above. That is, in the nanodevice manufacturing method according to the embodiment of the present invention, as described above, the nanostructures are arranged between the first electrode 11 and the second electrode 12, and then, for example, the flow path 17 is defined. Various nanodevices are produced by removing the first and second flow path forming portions 15 and 16 and electrically connecting the nanostructure to the first electrode 11 and the second electrode 12 respectively. can do.

FIG. 5 is a plan view of the nanodevice 20 according to the embodiment of the present invention, and FIG. 6 is an enlarged partial view of the gap region between the first electrode 21 and the second electrode 22 shown in FIG. 7 is a cross-sectional view taken along line AA of FIG.
As shown in FIGS. 5 to 7, the nanodevice 20 has a first electrode 21 and a second electrode 22 coaxially formed on a base 23 such as a glass substrate or a quartz substrate, that is, on the same line. The nanostructures 25 are juxtaposed along the longitudinal direction so as to straddle the first electrode 21 and the second electrode 22 in the gap between the first electrode 21 and the second electrode 22. . The flow path 27 is defined by the flow path forming section 26 along the longitudinal direction of the nanostructure 25. The flow path forming section 26 arranges the nano structures 25 in the electrode gap as described above. It corresponds to what is used when doing. As in the embodiment shown in FIG. 1, the first external connection electrode 28 extends from the first electrode 21 so as to intersect the flow path 27, and the second external connection electrode 29 extends from the second electrode 22. It extends so as to intersect the flow path 27.

  Here, as the base 23, in addition to an insulator such as a glass substrate, an insulating film may be formed on a metal or semiconductor substrate. Each of the first electrode 21 and the second electrode 22 includes an adhesion layer and an electrode layer. For example, a titanium layer having a thickness of 100 nm is adopted as the adhesion layer, and a platinum Pt layer is adopted as the electrode layer. preferable. The flow path 27 is preferably made of a material that can be peeled off in a later step, for example, PDMS, as in the above-described embodiment. The flow path 27 has, for example, a width of 150 μm and a height of 25 μm. For example, the gap between the first electrode 21 and the second electrode 22 may be 10 μm, and the length parallel to the flow path 27 of the first electrode 21 and the second electrode 22 may be 100 μm.

This nanodevice 20 exhibits non-linear IV characteristics, as will be apparent from examples described later. The nanodevice 20 can be manufactured by using the above-described method for arranging nanostructures, that is, following the following procedure.
As a first step, the first electrode 21 and the second electrode 22 are formed on the substrate 23 on the same axis, that is, at a distance so as to be on the same line in plan view. At that time, the first electrode 21 is formed integrally with the first external connection electrode 28, and the second electrode 22 is formed integrally with the second external connection electrode 29.
As a second step, the flow path 27 is formed on the base 23 in parallel along the arrangement direction of the first electrode 21 and the second electrode 22. At this time, a flow path forming portion 26 is provided on a base (not shown), and the base 27 and the base 23 on which the first and second electrodes 21 and 22 are formed are bonded to form a flow path 27. Alternatively, as described above, the flow path 27 may be formed using a spacer and a lid.
As a third step, an alternating voltage having a predetermined frequency is applied between the first electrode 21 and the second electrode 22, that is, between the first external connection electrode 28 and the second external connection electrode 29. While applying an alternating voltage therebetween, a dispersion in which a plurality of nanostructures are dispersed, for example, a suspension is passed through the flow path 27. Then, the nanostructures in the dispersion are parallel to each other along the flow, and one nanostructure is captured between the first electrode 21 and the second electrode 22 by induction electrophoresis, and the first electrode 21 is captured. One nanostructure 25 is disposed between the first electrode 22 and the second electrode 22.

  After that, the flow path forming portion 26 may be peeled off from the base 23, and further, a first contact electrode (“first first electrode”) is formed on one end of the first electrode 21 and the nanostructure 25. And a second contact electrode (also referred to as a “second conductive electrode”) on the other end of the second electrode 22 and the nanostructure 25. Thus, the electrical connection may be ensured.

  The nanodevice 20 described above is a two-terminal element, but the manufacturing method can be applied to an FET type nanodevice having, for example, three terminals. Hereinafter, the EFT type nanodevice will be described in detail. 8 is a plan view of the nanodevice 30 according to the embodiment of the present invention, FIG. 9 is a cross-sectional view taken along line BB in FIG. 8, and FIG. 10 is a cross-sectional view taken along line CC in FIG. . In the nanodevice 30, the first electrode 31 and the second electrode 32 are formed on the substrate 33 coaxially, that is, with a gap on the same line in plan view, and the first electrode 31 and the second electrode are formed. The nanostructures 35 are juxtaposed along the longitudinal direction so as to straddle the first electrode 31 and the second electrode 32 in the gap between the first electrode 31 and the second electrode 32. Here, the first electrode 31 has a stacked structure of an adhesion layer 31a and an electrode layer 31b, and the second electrode 32 has a stacked structure of an adhesion layer 32a and an electrode layer 32b. In the nanodevice 30, a third electrode 43 is further formed outside either the first electrode 31 or the second electrode 32. Here, like the first electrode 31 and the second electrode 32, the third electrode 43 is formed by a laminated structure of an adhesion layer and an electrode layer. The third electrode 43 extends in parallel with the direction intersecting the gap between the first electrode 31 and the second electrode 32.

  As shown in FIGS. 8 and 9, a first contact electrode 41 is formed on the first electrode 31 so as to partially cover the end of the nanostructure 35 on the first electrode side, A second contact electrode 42 is formed on the second electrode 32 so as to partially cover the end of the nanostructure 35 on the second electrode side. Here, the first contact electrode 41 has a stacked structure of an adhesion layer 41a and an electrode layer 41b, and the second contact electrode 42 has a stacked structure of an adhesion layer 42a and an electrode layer 42b. . Since the contact electrodes 41 and 42 are laminated, the nanostructure 35, the first electrode, and the second electrode form ohmic contacts, respectively.

  Further, a first protective layer 46 made of an insulating material is formed on the first electrode 31 except for both ends thereof, and a second made of an insulating material except for both ends thereof is formed on the second electrode 32. A protective layer 47 is formed, and a third protective layer 48 made of an insulating material is formed on the third electrode 43 except for both ends thereof. Here, an epoxy resin such as SU-8 is used as the insulating material.

  This nanodevice 30 is used in an electrolyte solution, and an EC-FET that functions as either a first electrode 31 or a second electrode 32 as a source electrode, the other as a drain electrode, and a third electrode 43 as a gate electrode. (Electrochemical-Field Effect Transistor) type nano device is constructed. This is also referred to as an electric double layer FET, because when a gate voltage is applied to the third electrode 43, an electric double layer having a molecular level thickness is formed on the surface of the nanostructure 35 through the electrolyte.

  A method for manufacturing the nanodevice 30 will be described. FIG. 11 is a plan view showing one step in the process of manufacturing the nanodevice 30 shown in FIG. First, the third electrode 43 is formed on the base body 33 together with the first electrode 31 and the second electrode 32 as in the process of manufacturing the nanodevice 20 described above, and then the flow path 37 is formed by the flow path forming portion 36. Form. Then, by applying the above-described nanostructure arrangement method, the nanostructures 35 are juxtaposed so as to straddle both ends of the first electrode 31 and the second electrode 32 as shown in FIG. Thereafter, the flow path forming portion 36 that defines the flow path 37 is removed to form contact electrodes 41 and 42, and then the first protective layer 46, the second protective layer 47, and the third protective layer 48 are formed. What is necessary is just to form. Since the nanodevice 30 is used in an electrolyte solution, the external connection electrodes 38, 39, and 49 are electrically connected to the ends of the external connection electrodes 38, 39, and 49 shown in FIG. 8 and a power source (not shown). It is preferable to provide an insulating layer or the like on the end portion of each.

Examples are given to further illustrate the present invention.
First, a ZnO nanowire was produced as a nanostructure by the following procedure.
An Au thin film with a thickness of 50 to 100 nm was coated on a Si substrate (100), and ZnO was grown on the substrate by a vapor-phase transport (VPT) method. At that time, ZnO powder and carbon powder were mixed so as to have the same mass ratio, used as raw materials, and reacted at 900 ° C. for 20 minutes using 100 sccm (cm ³ / min) argon gas as a carrier gas. In addition, ZnO nanowires can be similarly produced by coating a 0.005M dehydrated zinc acetate / ethanol solution without coating the Au thin film on the Si substrate.

  FIG. 12 shows the ZnO nanowires produced in the examples, (A) is an SEM image of what was produced on the substrate, and (B) is an enlarged image of (A). As shown in FIGS. 12A and 12B, nanowires were deposited on the silicon substrate. The length of the nanowire ranged from 40 μm to 120 μm. The nanowire was substantially cylindrical, and its radius was 50 nm to 300 nm. The aspect ratio was 60-400. Therefore, the length of the wire is very small compared to the radius.

  Next, the produced ZnO nanowire was dispersed in an isopropanol solvent. FIG. 13 is an optical microscope image showing a dispersion of ZnO nanowires. The dispersion concentration was a maximum of 10 particles / μl.

On the other hand, a nanodevice fabrication substrate 40 corresponding to FIG. 11 was fabricated by the following procedure.
14A shows a device mask design of the first, second, and third electrodes 31, 32, 43, etc., and FIG. 14B shows a device mask pattern when the microchannel 37 is stacked. As shown in FIG. 14A, a first electrode 31 and a second electrode 32 were formed on a glass substrate 33 with 200 nm-thick Ti and 100 nm-thick Pt by a sputtering vapor deposition method and a photolithographic method. At this time, the gap between the first electrode 31 and the second electrode 32 was 10 μm. Corresponding to the arrangement of the first electrode 31 and the second electrode 32, a flow path 37 was laminated on another glass substrate 34 by a flow path forming part 36 made of PDMS. The channel width was 100 μm. Thereafter, a substrate (also referred to as “electrode substrate”) 33 on which the first electrode 11 and the second electrode 12 are formed and a substrate (also referred to as “channel substrate”) 34 on which the flow path 37 is formed. And glued together. At that time, each surface of the electrode substrate 33 and the PDMS flow path forming portion 36 was subjected to oxygen plasma treatment.

  FIG. 15A is an SEM image of the electrode substrate 33 actually manufactured, and FIG. 15B is an SEM image in a state where the electrode substrate 33 and the flow path substrate 34 are actually bonded. In FIG. 15B, an image with reduced magnification is inserted.

  FIG. 16 shows a simulation result of the electric field gradient when the alternating voltage is applied to the first electrode 31 and the second electrode 32 shown in FIG. FIG. 5B is a diagram showing the electric field gradient on the surface of a predetermined height from the electrode 31 and the second electrode 32 in shades, and FIG. 5B is a diagram showing the gradient of the electric field gradient in the vertical section direction. In this calculation, commercially available software COMSOL based on the finite element method was used. In any of the figures, the slanted white line represents one nanostructure. 16 (A) and (B), the electric field gradient is concentrated at each electrode tip, suggesting that the nanostructure trapping interaction works most strongly at the first and second electrode tips. is doing.

Next, in the nanodevice fabrication substrate 40 fabricated as described above, an isopropanol solution (hereinafter referred to as “ZnO dispersion”) in which ZnO is dispersed while applying an AC voltage to the first electrode 31 and the second electrode 32. Was called from the inlet of the flow path 37. Then, it confirmed that ZnO nanowire was transferred, aligning in parallel with a laminar flow. When introducing the ZnO dispersion, an alternating voltage was applied to the first electrode 31 and the second electrode 32 to induce a dielectrophoretic force. The application condition of the DEP pulse was a frequency of 100 kHz and 10 Vpp. Confirm that the ZnO nanowires are captured by the first electrode 31 and the second electrode 32 within one minute when a DEP pulse is applied in a state where a dispersion obtained by dispersing ZnO nanowires as a dispersoid flows. did. As a result, as shown in FIG. 17, there is one wire between the first electrode 31 and the second electrode 32, as is apparent from the SEM image showing that the ZnO nanowire is captured between the electrodes. Of ZnO nanowires could be arranged.
The needle-like nanostructures that are not oriented in parallel with the flow path 37 and the nanowires that deviate from the line connecting the tips of the electrodes even in parallel with the flow path are captured by the first and second electrodes 31 and 32. I never did. Moreover, as the above-mentioned simulation result, the p-DEP force acting on the nanowire was extremely large in comparison with the fine particle system in the frequency region of 100 kHz. When the frequency of the voltage applied to the first electrode 31 and the second electrode 32 was set to a frequency lower than 100 kHz, the ZnO nanowire was broken.

  As described above, when the processing for arranging the nanowires was performed 15 times, the number of times that one ZnO nanowire was captured between the first electrode 31 and the second electrode 32 was 13, and the remaining Only two times, two or more nanowires were captured. Therefore, the success rate of capturing nanowires between only one electrode was about 80%.

  In the above-described results of the present embodiment, the regions where the electric field gradient is high are concentrated at the respective extreme points of the first electrode 31 and the second electrode 32 as in the above-described simulation results. This is probably because the probability of selectively capturing only one moving ZnO nanowire is extremely high. Thereby, a single nanowire can be selectively arranged between electrodes.

(Comparative example)
As a comparative example, a dispersion in which ZnO nanowires are dispersed in 10 ml of an isopropanol solution using only an electrode substrate without forming the flow path 37 is used between the first electrode 31 and the second electrode 32. Dropped in the vicinity of the gap. Even in this case, the p-DEP force acts in the vicinity of the first electrode 31 and the second electrode 32, and the phenomenon of securing one end of the ZnO nanowire is relatively likely to occur. However, the probability that the nanowire was captured so as to straddle both electrodes was extremely low. Further, if the DEP pulse is continuously applied for about 5 minutes to 10 minutes, the ZnO nanowires are stochastically captured by the first electrode 31 and the second electrode 32, but the ZnO nanowires are densely packed, and one ZnO nanowire is formed. Couldn't just capture.

  From the above, when this example and the comparative example are compared, it is possible to capture only one electrode gap in the electrode gap very quickly and easily using the channel and the induction electrophoresis.

Next, the characteristics of the fabricated nanodevice were evaluated.
When current voltage characteristics were measured by applying a DC voltage to the first electrode 31 and the second electrode 32, it can be said that the electrical connection between the captured single nanowire and the two electrodes is extremely stable with good reproducibility. .

The first electrode 31 and the second electrode 32 were connected to an electrometer, and the current-voltage characteristics were examined. FIG. 18A shows the current-voltage characteristics of the manufactured nanodevice, and FIG. 18B shows the current-voltage characteristics when the nanostructure is irradiated with light having different wavelengths.
From the current-voltage characteristics shown in FIG. 18A, it can be seen that a Schottky barrier is formed at the ZnO / Pt interface. Since a Schottky barrier is present at the junction interface between the Pt electrode and the ZnO nanowire, the current-voltage characteristics are nonlinear, and the current increases rapidly at −0.5 V or lower and 1.6 V or higher. This point can be explained by the fact that the asymmetric current-voltage characteristic is that the work function of platinum is 6.1 eV and the electrical affinity of ZnO is 4.5 eV.
We observed the photocurrent response when irradiated with light of different wavelengths. In FIG. 18B, an arrow A is a characteristic curve in a state where light is not irradiated, an arrow B is a characteristic curve in a state where light in a wavelength range of 520 nm to 550 nm is irradiated, and an arrow C is a wavelength. It is a characteristic curve in the state which irradiated the light of the range of 460 nm-490 nm. No photocurrent was observed particularly in these three characteristic curves. On the other hand, an arrow D is a characteristic curve in a state where light in a wavelength range of 360 nm to 370 nm is irradiated, and a photocurrent was observed for light in the ultraviolet region. In the embodiment, since the nanostructure is ZnO, Zn ²⁺ and O ²⁻ serve as an ion carrier.
Therefore, it was found that the nanodevice manufactured in this example can be applied as an optical sensor.

Current transient characteristics with respect to ON / OFF of UV light irradiation were investigated. For comparison, the photocurrent response of a substrate on which a ZnO thin film is formed (hereinafter referred to as “ZnO thin film substrate”) was also measured. FIG. 19A is a diagram showing a result of current transient characteristics with respect to ON / OFF of UV light irradiation to the nanodevice fabricated in this example, and FIG. 19B is a diagram showing a result of current transient characteristics of a ZnO thin film substrate. FIG. In either case, the horizontal axis represents time (seconds), and the vertical axis represents current (A).
As shown in FIG. 19A, in the nanodevice in which one ZnO nanowire is arranged, the current value increased 20 to 1000 times between ON and OFF of UV irradiation, and the response time was 10 seconds. . On the other hand, as shown in FIG. 19B, in the ZnO thin film substrate, the current value increased about twice as the UV irradiation was turned on and off, and the response time was 2 minutes.
In the nanodevice in which ZnO nanowires are arranged, it is speculated that the photocurrent is generated because the oxygen adsorbed on the ZnO surface layer is desorbed by UV light, and the excess negative charge becomes carriers and the photocurrent is generated. The Compared to the photocurrent response of the ZnO thin film substrate as a comparative example shown in FIG. 19B, it was found that the single ZnO nanowire device was superior in both response time and response current.

  As Example 2, the FET type nanodevice shown in FIG. FIG. 20 is an SEM image of the fabricated FET nanodevice. The main points different from the procedure prepared in Example 1 are that the third electrode 43 is formed simultaneously with the first electrode 31 and the second electrode 32, and on the ends of the first electrode 31 and the nanowire 35. The first contact electrode 41 is formed on the second electrode 32 and the second contact electrode 42 is formed on the end portions of the second electrode 32 and the nanowire 35, and the first electrode 31 is partially formed on the first electrode 31. The protective layer 46 is formed, and the second protective layer 47 is partially formed on the second electrode 32, and at the same time, the protective layer 48 is provided on the third electrode 43.

Specifically, the single ZnO nanowires are arranged between the gaps between the first electrode 31 and the second electrode 32 by a method combining induction electrophoresis and a flow path in the same manner as in Example 1, and then the adhesion layer 41a. , 42a are Ti layers and electrode layers 41b and 42b are Pt layers, and contact electrodes 41 and 42 are stacked. Thereby, each edge part of ZnO nanowire was fixed to the 1st electrode 31 and the 2nd electrode 32, respectively. As the first to third protective layers 46, 47, 48, the insulating layers were formed using Su-8. Thereafter, dodecanedioic acid (HOOC (CH ₂ ) ₁₀ COOH) was adsorbed on the surface of the ZnO nanowires to prevent etching of the ZnO nanowires in the electrolyte solution, specifically in the phosphate buffer solution. Note that the electrode width of the third electrode 43 serving as a gate electrode was set to 30 μm.

FIG. 21 shows current-voltage characteristics of the fabricated FET nanodevice. In the figure, a curve indicated by an arrow A is a current-voltage characteristic in a state where single ZnO nanowires are arranged, and a line indicated by an arrow B is a current when a Ti layer and a Pt layer are stacked as a contact electrode. Voltage characteristics.
The voltage and current applied between the first electrode 31 and the second electrode 32 are obtained by arranging ZnO nanowires in the gap between the first and second electrodes 31 and 32 as shown by an arrow A in FIG. In this state, although it is non-linear, it can be seen that by changing the Ti / Pt electrode as the contact electrode, the Schottky junction is changed to the ohmic junction.

The FET type nano device fabricated soaked in phosphate buffer as the electrolyte solution, the bias voltage applied to the third electrode 43, i.e. while changing the gate voltage V _G, the source and the second is the first electrode 31 The current value flowing between the electrode 32 and the drain was measured. FIG. 22 is a diagram showing I _SD -V _SD characteristics in an EFT nanodevice. The gate voltage _{V G} to + 0.5V to-0.5V was varied 0.1V intervals. From the FET characteristics shown in FIG. 22, it was found that a single ZnO nanowire exhibits the characteristics of an n-type semiconductor.

The FET type nano device fabricated soaked in phosphate buffer as the electrolyte solution, the source - drain voltage V _SD is constant, the source while varying the gate voltage V _G - current flowing between the drain I _SD and the gate current I _G And measured. _23, when fixing the _{V SD} to 0.5V, _I SD for _{V G,} it is a diagram illustrating a measured result indicating a relation between _{I G.} Leakage of the gate current I _G from the figure did not occur the influence of degradation of less ZnO (deterioration).

  According to the present invention, only one nanostructure can be easily arranged between the electrodes. Therefore, an inefficient process having a transcendence technique such as operating a single nanowire with a micromanipulator as in the prior art becomes unnecessary. That is, when using optical tweezers or the like, the apparatus becomes expensive and takes time to manufacture, and it is impractical to mass-produce the same device, but in the present invention, For example, since a single nanostructure can be arranged between electrodes in a short time without using optical tweezers or the like, it has industrial applicability and high convenience. Nanodevices with a single nanostructure exhibit electrical resistance characteristics with unique IV characteristics and can be applied to many biosensors such as memory elements, logical color elements, oxygen sensors, enzyme sensors, immunosensors, and cell sensors. be able to. Furthermore, optical response, electrochromism, electrochemiluminescence, electroluminescence, memory response, and sensing response can be observed.

10: Nanostructure array chip 11, 21, 31: First electrode 11a: Tip portion of first electrode 11b: End portion of first electrode 12, 22, 32: Second electrode 12a: Second electrode Electrode tip portion 12b: second electrode end portion 13, 14, 23, 33, 34: substrate (substrate)
15, 16, 26, 36: flow path forming part 17, 27, 37: flow path (micro flow path)
18, 28, 38: first external connection electrode 18a: outer end portion of the first external connection electrode 19, 29, 39: second external connection electrode 19a: outer end portion of the second external electrode 20, 30 : Nanodevice 25, 35: Nanostructure (nanowire)
31a, 32a, 41a, 42a: Adhesion layer 31b, 32b, 41b, 42b: Electrode layer 40 Nanodevice fabrication substrate 41, 42: Contact electrode 43: Third electrode 43a: Outer end of third electrode 46 : First protective layer 47: second protective layer 48: third protective layer

Claims (7)

  It is defined along the arrangement direction of the first electrode and the second electrode while forming an alternating electric field between the first electrode and the second electrode which are provided at intervals. The nanostructure is arranged so as to straddle the first electrode and the second electrode by flowing a dispersion in which a plurality of nanostructures are mixed with the flow path. Array method.   The end on the second electrode side of the first electrode becomes narrower as the tip is reached, and the end on the first electrode side of the second electrode becomes the tip. The method for arranging nanostructures according to claim 1, wherein the width is narrow. Forming a first electrode and a second electrode on a substrate at an interval;
Providing a flow path along the arrangement direction of the first electrode and the second electrode on the substrate;
While applying an alternating voltage between the first electrode and the second electrode, a dispersion in which a plurality of nanostructures are mixed is caused to flow through the flow path, and the nanostructures are induced to the first by electrophoretic migration. Capturing between the electrode and the second electrode, and arranging the nanostructure so as to straddle the first electrode and the second electrode;
A method for manufacturing a nanodevice, comprising: Furthermore, removing the flow path forming part that defines the flow path;
A first conductive electrode is formed on one end of the nanostructure and the first electrode, and a second conductive is formed on the other end of the nanostructure and the second electrode. Forming an electrode;
The manufacturing method of the nanodevice of Claim 3 containing this.   The end on the second electrode side of the first electrode becomes narrower as the tip is reached, and the end on the first electrode side of the second electrode becomes the tip. The method for producing a nanodevice according to claim 3, wherein the width is narrow.   A base, a first electrode provided on the base, a second electrode provided on the base at a distance from the first electrode, the first electrode, and the second electrode And a flow path forming part that defines a flow path along the direction in which the nanostructures are to be arranged.   The nanodevice manufacturing substrate according to claim 6, wherein the nanostructures are arranged between the first electrode and the second electrode.